This core project will provide standardization of surgery, injury, and behavioral assessment for all laboratory investigators utilizing the rat model of fluid percussion traumatic brain injury (TBI). This will help to insure scientific control, comparability of results, and economic prudence. This core project will provide a central facility for surgical preparation of rats for fluid percussion TBI. This facility will also produce injury in a standardized manner such that the results from different subprojects will be comparable. This project will also provide behavioral testing including assessment of transient behavioral suppression (measures of traumatic unconsciousness) and assessment of long-term behavioral deficits which include measures of vestibulomotor function and refined motor function and coordination. This core project will also provide periodic histopathological analysis of selected rat brains to insure the consistency of injury. This facility will maximize the use of personnel, space, and equipment in order to provide a most efficient, centralized and fiscally prudent core center for well-con-trolled rat surgery, injury and behavioral assessment.